You're going to need to explain what you mean by "shakes", but I'm going to venture out and say no, that's not normal. Is the computer on a wobbly table?
It's usually in my lap. When I am typing I can see the screen go back and forth but the hinge stays in place.
Well does the screen feel loose in your hand?
What do you mean by that? When opening/closing the laptop it seems fine. It's just when I am typing that I see it wobble a little bit.
I mean if you hold your screen from the top/side and add a little force while it's in the normal open position, does it move very loosely? If not then this seems like a non-issue, and completely dependent on how you position yourself & your macbook.